KLH model 12

[Penn42]

IME the sealant is thin enough that you'd have to really be trying to lather it on to over do it on the first coat. Get ready for a huge difference!

 

[Phydeaux]

IME the sealant is thin enough that you'd have to really be trying to lather it on to over do it on the first coat. Get ready for a huge difference!

At first I was putting a bit too much before I could tell how far it was spreading but tried to even it out with the brush as much possible.
Was having a hard time seeing since i didn’t wanna drag these heavy suckers outside.
a flashlight was really helpful to see what spots I was missing.

you normally ever have to do a second coat in your experience? The twelves were really dry but I was a little more liberal in applying to those woofers in particular.

 

[Phydeaux]

Thanks

Nice!! I'm glad you got them working let us know how they sound

Thanks, I’m really happy to finally have some speakers that actually work after all this time.
They sounded great already but I think the bass was kinda muddying up everything else...sometimes parts I’m familiar with in a song weren’t as defined in the mix as I’m used to. Hoping the tighter bass will cure that.

will share my thoughts after some long overdue listening!

 

[Penn42]

At first I was putting a bit too much before I could tell how far it was spreading but tried to even it out with the brush as much possible.
Was having a hard time seeing since i didn’t wanna drag these heavy suckers outside.
a flashlight was really helpful to see what spots I was missing.

you normally ever have to do a second coat in your experience? The twelves were really dry but I was a little more liberal in applying to those woofers in particular.

I've never had a KLH woofer that wasn't dry as a bone so I've always applied a very light second coat. I do this by dipping maybe 1/3 of an acid brush in the sealant, letting it drip off excess for a few seconds, dabbing the damp brush every couple inches around half the circumference of the surround, then going back and spreading the it evenly.

That's how I've done the half dozen sets I've restored and all have had great bad response to my ears.

 

[Phydeaux]

I've never had a KLH woofer that wasn't dry as a bone so I've always applied a very light second coat. I do this by dipping maybe 1/3 of an acid brush in the sealant, letting it drip off excess for a few seconds, dabbing the damp brush every couple inches around half the circumference of the surround, then going back and spreading the it evenly.

That's how I've done the half dozen sets I've restored and all have had great bad response to my ears.

I may just do that, have about half the large container left so should be more than enough to go over everything again.
probably going to give em a quick test first since I’m a bit antsy to hear the difference. Thanks for the tip.

 

[Dswankey]

Thanks, I’m really happy to finally have some speakers that actually work after all this time.They sounded great already but I think the bass was kinda muddying up everything else...sometimes parts I’m familiar with in a song weren’t as defined in the mix as I’m used to. Hoping the tighter bass will cure that.

Good Bass is a must!

 

[Phydeaux]

Good Bass is a must!

Agreed...I’m shocked that speakers from the 60’s sound this good. Been missing out all these years before getting into vintage stereo...wish I would have jumped in ten years ago when I first got the urge now that the prices are astronomical...

 

[Phydeaux]

After doping the surrounds and letting the caps burn in I noticed a big difference in the bass response and overall I think these speakers sound great with most of the music I’ve thrown at them....but since my listening room is way too small and they’re currently being driven by my 30wpc sansui amp I don’t think I’m getting the most out of them that I could be. Can’t do much about that right now but am searching for an amp that might suit these better.

For now I’m thinking of going the weather stripping route to ensure the drivers are properly sealed to the cabinets since a previous owner used some kind of putty and I’m not too thrilled with the job they did. Thinking weather stripping for the woofers and maybe cutting out some kind of closed cell foam sheets for the mids and tweeters.

Maybe hard to tell in the photos but the drivers don’t all seem like they’re sitting flush and I have a feeling there’s some leaking happening from one or more driver.

 

[alteclipsch]

After doping the surrounds and letting the caps burn in I noticed a big difference in the bass response and overall I think these speakers sound great with most of the music I’ve thrown at them....but since my listening room is way too small and they’re currently being driven by my 30wpc sansui amp I don’t think I’m getting the most out of them that I could be. Can’t do much about that right now but am searching for an amp that might suit these better.

For now I’m thinking of going the weather stripping route to ensure the drivers are properly sealed to the cabinets since a previous owner used some kind of putty and I’m not too thrilled with the job they did. Thinking weather stripping for the woofers and maybe cutting out some kind of closed cell foam sheets for the mids and tweeters.

Maybe hard to tell in the photos but the drivers don’t all seem like they’re sitting flush and I have a feeling there’s some leaking happening from one or more driver.

FWIW, my opinion would be to use closed cell foam for all of them if you're not going to use something like Mortite (which makes a really good, non-hardening seal).

 

[Phydeaux]

Also figured I owed something semi informative to thread so here’s a better late than never before and after pic of one of the contour boxes.

the local tech used a combination of nichicon electrolytics and Dayton film caps.

 

[Phydeaux]

FWIW, my opinion would be to use closed cell foam for all of them if you're not going to use something like Mortite (which makes a really good, non-hardening seal).

I like the closed cell weather stripping idea for the woofers, someone mentioned in another thread about using two 3/8x1/16 strips on either side of the screw holes so if the inner strip fails the outer one would still keep it from leaking.
I do need to figure out what kind of sheets of closed cell foam would work for the mids and tweeters since I think the weather stripping would be more difficult to apply to those.

 

[Penn42]

I bought I whole role of 1/16 neoprene from Lowe's for cutting speaker gaskets. Works great. $18 for a 39"x78" sheet, so probably a lifetime supply, and it will fully decompress if you ever have to remove a driver meaning you can reuse it (the decompression takes a couple hours though).

 

[Mr. Cryalot]

In general this is what I would do. More specifically I would try to do film for the mids/tweeters and NPE for the woofers. It shouldn't be all that hard to figure out what's what, the 4 wires from the boxes to the speakers are Ground, Woofer, Midrange, Tweeter. The contour boxes are kind of a rats nest though, you'll have to trace it out.

I actually ended up with two sets of contour boxes, one I redid with film (the thread that was linked), one I redid with Parts Express NPE. Honestly I think they both sounded fine, KLH tweeters were never the last word in extension or detail and anything will be better than the caps that were in there from the factory.

Keep your fingers crossed that the tweeters aren't blown, they're unique to the Model 12 (they should be stamped M12 on the faceplate). Worse comes to worse Model 5 tweeters should be similar, although I would replace both even if only one is blown. Model 12 parts do show up on eBay occasionally, you'll need to be patient though.

In my experience they like big solid state power. I tried them with a couple tube amps and they sounded flat, but a couple hundred watts really woke them up.

The fine principals and members at CSP, including Roy C himself. ( Forgive me for speaking for you Roy) of which I am a member myself....Have debated for nearly 8 decades ( it seems like) on this topic. (Originating from the "is the model 5 woofer same as twelve? Debate/Civil war.)

#1

"m-12" stamp or not, the model five and twelve tweeter and mids ARE IDENTICAL in every conceivable ( and non conceivable) way. And yes they came from the factory that way in many cases.

#1(a)

thus any tweeter from a model twelve, model five or twenty three will have an identical frequency response and "tonal" quality. No other KLH tweeter will.

2) a model 5 woofer is different from the model 12 woofer. They look similar in every way- basket size-same diameter.... The model 12 has a double magnet. therefore the 5 has a single magnet- the difference.

Apparently towards the end of the model 12's run they started throwing model 5 woofers in...causing confusion lasting however many decades its been. If you've heard refurbished or rebuild set a model twelves with the proper woofer in it you automatically know you're listening to a proper refurb. As it bests the 3A handily ( I'm referring to mostly (all!!) low end extension and that one was subjective I admit).

I've seen with my own eyes original owners sets of model fives with "m-12 stamp". As well as model twelve tweets original with no stamp at all. Klh made all of their own drivers, and consistency with anything other than the quality of the build- sound quality...
....is the only thing you could rely on.

******

a few words on KLH capacitors, recapping said capacitors, and how we know Henry Kloss clipped coupons at home
..
..Recapping anything KLH or otherwise...

1) unless you've a super early set of fours sixes, sevens, few more. Those have (pio) "oil" caps- that to this day... I've never found one out of spec. Leave those in. The polar opposite of....

( Similarly to the ola having a masonite adapter rings because Henry found a ton of 12" baskets, the speaker needing a 10" woofer be damned - a deal is a deal and he made it work. I believe the cap situation was similar.)

2) ...those damn Sprague capacitors. ( 4/5 "dead tweeters" in my experiences, suddenly rise from the dead with new capacitors.

Also please take Ken Kantor's FIRM advice and replace like capacitors with like capacitors. They were designed that way for a reason ( in this case, mainly because it's all there were-) nevertheless if you want to
A) hear the speaker as designed
B) survive the heart attack getting into a cap debate w anyone will cause, or

C) save a few hundred dollars with no measurable improvement on SQ otherwise, which many do....

..... stick with like caps. Mundorf z caps I like. ( If Ken's reading or using esp... I never said this and I'll take it to my grave! but bypass with film or poly on the mids and tweet if you must!).

Scottie

You've all seen a model 5 woofer. this is a model 12.

 

[Mr. Cryalot]

One of my favorites as well, almost always end up listening to the whole album when I just had one track or two in mind....especially love
‘On the bus’ and ‘lucile’.


And thanks, the thread I found from jkent regarding the twelves was very informative and basically answered my question...although after seeing his work on his and others contour boxes...I’m half tempted to see if he’d do mine as well....seems like a nice guy and knows his stuff.

You are correct he is actually a very very nice guy. Hi John, Scottie. And knows the model twelve better than anyone.